Calibration systems of the ATLAS Tile Calorimeter

TileCal is the hadronic calorimeter covering the most central region of the ATLAS experiment at the LHC. This sampling calorimeter uses iron plates as absorber and plastic scintillating tiles as the active material. Scintillation light produced in the tiles is transmitted by wavelength shifting fibers to photomultiplier tubes (PMTs). The resulting electronic signals from the over 10000 PMTs are measured and digitized before being transferred to off-detector data-acquisition systems. A multi-faceted calibration system allows to monitor and equalize the calorimeter response at each stage of the signal production, from scintillation light to digitization. This calibration system is based on signal generation from different sources: a Cs radioactive source, laser light, charge injection and minimum bias events produced in proton-proton collisions. This talk presents a brief description of the different TileCal calibration systems and presents the latest results on their performance in terms of calibration factors, linearity and stability.